Programmable micropillars via laser texturing for on-demand wetting transitions

On-demand wetting transitions enable surfaces with dynamic control over liquid interactions, enabling applications in microfluidics, soft robotics, and self-cleaning technologies. In this work, we developed superomniphobic surfaces with programmable texture by simple, scalable and solvent free CO 2 laser texturing of shape memory polymers to obtain re-entrant texture, followed by surface modification to impart low solid surface energy. Our stimuli responsive superomniphobic surfaces are not only repellent to aqueous and organic liquids, but also display reversible on-demand wetting transitions for multiple cycles on exposure to external stimuli due to rearrangement of molecular chains. We demonstrated the ex situ and in situ on-demand wetting transitions using contact mode (heat) and non-contact mode (NIR laser). We also demonstrated the reversible and erasable liquid patterns on superomniphobic surfaces with programmable wettability. We envision that superomniphobic surfaces with programmable wettability will have wide range of applications including rewritable liquid patterns, liquid droplet manipulations, lab on chip devices and selective chemical reactions.